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In a high pressure gradient pump, each different mobile phase is delivered by an individual pump head and then the mobile phases are mixed at the pump outlet. In a low pressure gradient pump, different mobile phases are mixed using a valve before entering the pump head.
As a result of the fact that the low-pressure gradient design uses only one pump head, it is of lower cost. It can also use more types of mobile phase without significant increase of cost.
Since solvent mixing point is much closer to the column head in the high-pressure gradient design, it provides a much faster gradient. This is measured using delay volume. The value can be 50-300 uL for high pressure gradient pump and can be 2 to 3 times larger for a low pressure gradient pump. A small delay volume is important when the analysis time is short or the flow rate is low. If the delay volume is too large, it become impossible to obtain reproducible gradient run since the planed composition cannot reach the column head before a run is finished.
In high-pressure gradient HPLC, the mobile phase is pressurized to deliver a gradient of solvent mixtures. This allows for more precise control over the separation of compounds based on their differing affinities for the stationary phase. In contrast, low-pressure gradient HPLC operates at lower pressures and uses a manually adjusted gradient system, providing less precise control over the separation process.
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What is Difference Between HPLC UV detector Spectrophotometer uv detector?
HPLC UV detector is a component used in high-performance liquid chromatography (HPLC) to monitor eluent absorbance, while a spectrophotometer UV detector is a standalone instrument used to measure the absorption of light at different wavelengths. HPLC UV detectors are specifically tailored for chromatography applications, whereas spectrophotometer UV detectors are more versatile and used for various analytical purposes.
What is difference bet GLC and HPLC?
GLC (Gas Liquid Chromatography) uses gas as the mobile phase and liquid as the stationary phase, while HPLC (High Performance Liquid Chromatography) uses liquid as the mobile phase and a solid or semi-solid stationary phase. GLC is mainly used for volatile compounds, while HPLC is more versatile and can analyze a broader range of compounds.
How do you use resolution factor in HPLC?
The resolution factor in HPLC is used to quantify the degree of separation between two adjacent peaks on a chromatogram. It is calculated by dividing the difference in retention times of the two peaks by the sum of their peak widths. A higher resolution factor indicates better separation between the peaks.
What does HPLC stand for?
HPLC stands for High Performance Liquid Chromatography. It is a technique used to separate and analyze components in a liquid mixture based on their interactions with a stationary phase.
What process that uses pressure to separate substances in a solution?
The process you are referring to is likely a type of chromatography, known as high pressure liquid chromatography (HPLC). In HPLC, a liquid mobile phase is passed through a column of stationary phase under high pressure, separating the components of a mixture based on their interaction with the stationary phase.
What is difference between high pressure liquid chromatography and high performance lequid chromatography?
High pressure liquid chromatography (HPLC) and high performance liquid chromatography (HPLC) are often used interchangeably. HPLC refers to modern liquid chromatography systems with high resolution and efficiency, while high pressure liquid chromatography specifically highlights the use of higher pressures in the system to improve separation and speed. Both terms generally refer to the same chromatographic technique.
What is difference between isocratic and gradient hplc?
In isocratic HPLC, the mobile phase composition remains constant throughout the entire run, leading to constant elution times for all analytes. In gradient HPLC, the mobile phase composition is changed during the run, allowing for better separation of complex mixtures by adjusting the solvent strength over time.
What is Difference Between HPLC UV detector Spectrophotometer uv detector?
HPLC UV detector is a component used in high-performance liquid chromatography (HPLC) to monitor eluent absorbance, while a spectrophotometer UV detector is a standalone instrument used to measure the absorption of light at different wavelengths. HPLC UV detectors are specifically tailored for chromatography applications, whereas spectrophotometer UV detectors are more versatile and used for various analytical purposes.
What is dead volume HPLC?
The dead volume in HPLC is 137.45. The dead volume in science is used in retention measurements and also in thermodynamic studies and the abbreviation HPLC stands for High Pressure Liquid Chromatography.
What is difference bet GLC and HPLC?
GLC (Gas Liquid Chromatography) uses gas as the mobile phase and liquid as the stationary phase, while HPLC (High Performance Liquid Chromatography) uses liquid as the mobile phase and a solid or semi-solid stationary phase. GLC is mainly used for volatile compounds, while HPLC is more versatile and can analyze a broader range of compounds.
Why ordinary liquid pump cannot be used in hplc system?
An ordinary liquid pump cannot be used in HPLC systems because HPLC requires pumps that can generate high pressure to push solvents through the column at a constant and precise flow rate. Ordinary pumps do not provide the level of pressure and flow rate control needed for HPLC separations, which can negatively impact the accuracy and reproducibility of chromatographic results. HPLC pumps are specifically designed to handle the high pressures and flow rates required for efficient separations.
How do you use resolution factor in HPLC?
The resolution factor in HPLC is used to quantify the degree of separation between two adjacent peaks on a chromatogram. It is calculated by dividing the difference in retention times of the two peaks by the sum of their peak widths. A higher resolution factor indicates better separation between the peaks.
What does HPLC stand for?
HPLC stands for High Performance Liquid Chromatography. It is a technique used to separate and analyze components in a liquid mixture based on their interactions with a stationary phase.
What process that uses pressure to separate substances in a solution?
The process you are referring to is likely a type of chromatography, known as high pressure liquid chromatography (HPLC). In HPLC, a liquid mobile phase is passed through a column of stationary phase under high pressure, separating the components of a mixture based on their interaction with the stationary phase.
Why pressure is important in HPLC?
Pressure is important in HPLC to maintain the flow rate of the mobile phase through the column, which is necessary for efficient separation of compounds. The pressure also helps to ensure that the analytes are pushed through the column at a constant rate, resulting in consistent and reliable chromatographic results. Adequate pressure is needed to overcome frictional forces within the system and to prevent band broadening.
How do you distinguised np-hplc and rp-hplc?
NP-HPLC (normal phase HPLC) separates compounds based on their polarity, where the stationary phase is polar and the mobile phase is nonpolar. RP-HPLC (reverse phase HPLC) separates compounds based on their hydrophobicity, where the stationary phase is nonpolar and the mobile phase is polar. RP-HPLC is more commonly used due to its versatility and ability to handle a wider range of compounds.
Retention time calculation for hplc?
why RT was shifting & how to RT calculation in HPLC
